Hair care compositions and methods of use

ABSTRACT

Hair care compositions including from about 0.005% to about 5% apigenin; from about 0.15% to about 12% of a solubilizing agent, wherein the solubilizing agent comprises an amine functional group; and at least about 20 weight percent of an aqueous carrier, where the composition has a pH ranging from about 3 to about 10, and methods of making the same are provided. These hair care compositions can be applied to any area of the scalp or hair where healthier hair appearance is desired.

FIELD OF THE INVENTION

The present invention relates to hair care compositions comprising oneor more actives useful for regulating mammalian hair growth, increasinghair diameter, and/or delaying the appearance of gray hair, and methodsof use thereof.

BACKGROUND OF THE INVENTION

Many attributes contribute to the appearance of hair considered to beattractive. For instance, hair with a full and thick appearance is verydesirable. In contrast, hair with a thin appearance is not asattractive, and can even lead to a perception that the thin-hairedindividual is older than their chronological age. Additionally, theappearance of gray hair can also lead to the perception that anindividual is older than their chronological age. Furthermore, thin hairand gray hair can be more difficult to style, and typically cannot bestyled into as many hairstyles, leaving the individual frustrated andwith an unkempt appearance. Because of the foregoing problems associatedwith thin hair and graying hair, many individuals expend great effortand time on grooming, yet still do not attain their desired hairstyleand appearance. This can lead to frustration and/or lack of confidencein his or her appearance. These problems can be experienced by bothfemale and male consumers and at a variety of ages.

The flavone Apigenin, which is known to have antioxidant andanti-inflammatory properties, has been proposed to stimulate hair growththrough various biological pathways to increase the fullness and/orthickness of hair appearance and reduce the appearance of gray hair.However, apigenin possesses poor solubility in many solvent systems andthus it is difficult to prepare compositions with efficacious quantitiesof solubilized apigenin. In view thereof, there is a need to provideconsumers with a hair care composition that includes enhancedconcentrations of apigenin.

SUMMARY OF THE INVENTION

The present invention relates to hair care compositions and methods thatcan help increase the appearance of fuller and/or thicker hair and/orreduce the appearance of gray hair, thus resulting in healthier andyounger-looking hair. This result is achieved by increasing the diameterof hair shafts and follicles, increasing the number of hairs, reducingthe emergence of gray hairs, growing longer hair, and/or having hairwith less damage.

According to one embodiment, a hair care composition comprising aneffective amount of a hair growth stimulating agent for the purpose ofimproving the appearance of the hair is provided. The hair carecomposition comprises from about 0.005% to about 5% apigenin; from about0.15% to about 12% of a solubilizing agent wherein the solubilizingagent comprises an amine functional group; and at least about 20 weightpercent of an aqueous carrier. In one aspect of this embodiment, thecomposition has a pH ranging from about 3 to about 10.

According to yet another embodiment, a process for preparing a hair carecomposition is provided, the method includes (i) mixing apigenin and asolubilizing agent at a temperature sufficient to allow dissolution ofthe apigenin in the solubilizing agent to form a premixture, wherein theweight ratio of apigenin to the solubilizing agent ranges from about1:50 to about 1:4, (ii) combining the premixture with an aqueous carrierto form the hair care composition, and (iii) optionally, adjusting a pHof the hair care composition with acid to within a range from about 3 toabout 10.

These and other features, aspects, and advantages of the claimedinvention will become evident to those skilled in the art from a readingof the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a chart showing comparative skin penetration results ofseveral hair care compositions in accordance with an embodiment of thepresent invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

While the specification concludes with the claims particularly pointingand distinctly claiming the invention, it is believed that embodimentsof the present invention will be better understood from the followingdescription. In all embodiments of the present invention, all weightpercentages are by weight of the total composition, unless specificallystated otherwise. All ratios are weight ratios, unless specificallystated otherwise. All ranges are inclusive and combinable. The number ofsignificant digits conveys neither limitations on the indicated amountsnor on the accuracy of the measurements. All numerical amounts areunderstood to be modified by the word “about” unless otherwisespecifically indicated. All measurements are understood to be made at25° C. and at ambient conditions, where “ambient conditions” meansconditions under about one atmosphere of pressure and at about 50%relative humidity. All such weights as they pertain to listedingredients are based on the active level and do not include carriers orby-products that may be included in commercially available materials,unless otherwise specified.

As used herein, the term “hair care compositions” are compositions thatare applied to the hair and/or the skin underneath the hair, includingcompositions used to treat or care for the hair. Products contemplatedby the phrase “hair care composition” include, but are not limited toafter-shave tonics and lotions, creams, emulsions, foams, hairconditioners (rinse-off and leave-on), hair colorants, hair tonics,liquids, lotions, mousses, propellant lotions, shampoos, shave gels,temporary beard hair dyes, and the like.

“Hair growth stimulating agent” includes any material that can increaseor extend an anagen phase, or provide the appearance of increasing theanagen phase of mammalian hair growth, when an effective amount of acomposition containing a hair growth stimulating agent is topicallyapplied to the desired region over a result-effective period of time.All relative terms used in connection with hair growth stimulation areunderstood to mean that the benefit observed is relative to that whichis observed or would be expected without the exposure of a compositiondescribed herein. These observations include, but are not limited toincreasing the diameter of hair shafts and follicles, increasing thenumber of hairs, delaying the appearance of gray hairs, growing longerhair, and/or having hair with less damage.

“Increase the appearance of fuller and thicker hair” means the diametersof hair follicles and/or shafts in the subject region of hair (e.g.,scalp) are increased by a statistically significant amount, when aneffective amount of a composition of the present invention is topicallyapplied to the desired region over a result-effective period of time.

“Delay the appearance of gray hair” means the rate of gray hair emergingis delayed. It is accepted that canities (i.e., natural whitening orgraying of the hair) is associated with a decrease in melanin in thehair shaft. The onset or degree of canities is associated with aging,and thus the delaying or decreasing the appearance of gray hair providesa younger looking appearance. The rate of gray hair emergence can bemeasured by visual observation and by the method described in Japanesepatent application 2005-296352A assigned to Shiseido. The countingmethod consists of designating a 50 mm×10 mm area on either side of thefrontal scalp and collecting all the hairs within the area and counting1000 hairs cut from the area. Gray hairs and pigmented hairs are bothcounted. The process is repeated monthly, or as desired, and the percentof gray hairs is calculated.

“Mammalian hair,” as referenced herein, includes hair on any part of thebody of a mammal, and can include but is not limited to facial, cranial,or body hair. For instance, it can include hair on the scalp, head,neck, beard, moustache, eyebrows and sideburns hair.

The term “topical application,” as used herein, means to apply or spreadthe compositions of the present invention onto the surface of thekeratinous tissue from which the hair to be affected grows.

The term “dermatologically-acceptable,” as used herein, means that thecompositions or components thereof so described are suitable for use incontact with mammalian keratinous tissue without undue toxicity,incompatibility, instability, allergic response, and the like.

The term “effective amount,” as used herein, means an amount of acompound or composition sufficient to increase the diameter of theshafts in the subject region of hair by a statistically significantamount, to increase the hair density (number of hairs per area) by astatistically significant amount, and/or to delay the appearance of grayhair by a statistically significant amount.

The term “solubilizing agent,” as used herein means a solvent orsolvent-based solution that solubilizes the hair growth stimulatingagents disclosed herein.

As used herein, “apigenin” includes salts or complexes thereof.Exemplary apigenin salts include amine salts.

Briefly, as is commonly known by those skilled in the art of the instantdisclosure, the hair cycle consists of three phases. The first phase, orgrowth phase, is known as anagen and lasts, on average, between threeand four years. The second phase consists of discontinued growth over aperiod of two to three weeks. This phase is called catagen. The lastphase, called telogen, is the phase where the hair falls out. This phaseoccurs fairly slowly, over the course of three to four months, as thebulbar zone of the hair follicle regresses and the hair shaft detachesand is expulsed towards the surface of the skin.

In accord with one embodiment of the present invention, a hair carecomposition comprising apigenin, and optionally one or more hair growthstimulating agents, is applied to the scalp and/or the base of the hairon the scalp, to increase the appearance of healthier andyounger-looking hair.

Applicants have found that a topical application of one or more hairgrowth stimulating agents to regions where the appearance of more hairis desired can actually improve the appearance of the region by havingan appearance of thicker and/or fuller hair and/or delay the appearanceof gray hair.

Although not wishing to be limited by theory, it is believed thattopical application of various hair growth stimulating agents can: (1)interrupt or inhibit an inflammatory cycle at the hair follicles, whichin turn may extend the anagen phase of the follicles; (2) stimulateaquaporin 3 (“AQP3”) up-regulators, which in turn may result in thickerhair shafts and follicles; and/or (3) stimulate the production ofmelanin in hair melanocytes, which in turn may delay the emergence ofgray hair. Accordingly, the topical application of the hair carecompositions may also help to slow the rate in which hair leaves theanagen phase, stimulate AQP3 up-regulators, delay the appearance of grayhair, or combinations thereof. The increase in the diameter of the hairshafts and follicles leads to the appearance of hair that is thicker andfuller. Furthermore, the topical application can lead to the appearanceof younger looking hair, since hair diameter is known to decrease withone's chronological age and the appearance of gray hair can be delayed.

The topical application of a hair care composition of present inventioncan aid in lengthening the anagen phase. The lengthening of the anagenphase can be achieved by either blocking the transition from anagenphase to telogen phase or by inhibiting the transition from anagen phaseto telogen phase. The hair follicles are in a growing phase (anagen) orin a resting phase (telogen). Follicles are predominately in the anagenphase. The anagen phase may typically last for approximately 2 to 10years, with an average duration of about 3 to 4 years that can varydepending on a variety of factors. Conversely, the telogen phase is muchshorter and may typically last for about 3 to 4 months. In general, aperson will have approximately 94% of the follicles in anagen phase and6% of the follicles in telogen phase. Each month approximately 2% of thefollicles leave anagen phase and transition to telogen phase and at thesame time approximately 2% of the follicles leave telogen phase andtransition to anagen phase. With the application of the hair carecompositions of the present invention, the approximately 2% of thefollicles leaving anagen phase can be either blocked or delayedresulting in an increased percent of hair follicles in anagen phase. Theincrease in the amount of follicles in anagen phase increases the hairdensity on the head. It is believed that the length of the anagen phasecan be increased from about 2 weeks to about 2.5 months. The increase inhair density (number of hair on a certain area of the scalp) can bemeasured. In one embodiment of the present invention, the hair densitywill increase by about 2 hairs/cm², preferably by about 3 hairs/cm², andin some embodiments greater than 4 hairs/cm². The benefits of theincreased anagen phase, hair density, and hair diameter and the delay ofgray appearance will result in a person's hair looking from 3 or moreyears younger.

A. Hair Care Compositions

In one aspect, the present invention provides hair care compositionsthat can be used to increase the appearance of thicker and fuller hair.The hair care composition comprises at least one hair growth stimulatingagent. According to embodiments of the present invention, the hairgrowth stimulating agent comprises a flavonoid compound, apigenin (whichis also known as 4′,5,7-trihydroxyflavone or5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one) in a safe andeffective amount. The hair care composition further includes asolubilizing agent having an amine functional group contained therein,and an aqueous carrier, wherein the composition has a pH ranging fromabout 3.0 to about 10. Optionally, the hair care compositions canfurther comprise other dermatologically-acceptable additives and/or anydesired suitable optional ingredients.

1. Apigenin

The hair care composition of the present invention includes theflavonoid, apigenin, which is a nonmutagenic citrus bioflavonoid presentin many types of plants and vegetables. Examples include, but are notlimited to, grapefruit, parsley, thyme, chamomile, apples, celery,basil, oregano, tarragon, cilantro, yarrow, kelp, camellia, and passionflower. Although apigenin can be found in many of plants and vegetablesin low quantities along with many other flavonoids, catechins, and othernaturally-occurring compounds, the total concentration of apigenin inthese materials varies greatly and there may not be enough apigeninpresent in these materials to be useful for the present invention. Assuch, for the present invention, the apigenin is in a purified state andsubstantially free of other compounds. As used herein,“substantially-free of other compounds” means that the apigenin is atleast 50 wt % pure. For example, according to one embodiment, theapigenin may at least 90 wt % pure, at least 95% pure, or at least 98%pure. For the present invention, the apigenin itself must be present inan amount of at least 0.005% based on the total composition. Theapigenin may be present in amount of greater than about 0.1%, 0.15%,0.2%, 0.25%, 0.3%, 0.4%, 0.5%, 0.7%, 0.9%, 1%, 2%, 3%, or 4%. Theapigenin is typically present in an amount of less than about 5%, 4%,3%, 2.5%, 2%, 1.8%, 1.6%, 1.5%, 1.4%, 1.3%, 1.2%, 1%, 0.9%, 0.8%, 0.7%,0.6%, 0.5%, 0.4%, 0.3%, 0.2%, or 0.1%.

2. Solubilizing Agent

Apigenin is solid in its pure form and is practically insoluble (i.e., asolubility of less than 1 mg/ml) in water and nearly all solventssuitable for pharmaceutical, cosmetic, and food additive formulations.As such, one major obstacle for formulators is the need for apigenin tobe provided from a stock solution (i.e., a premixture) utilizing asolubilizing agent that is compatible with the base formulation. Thechoice of such solubilizing agents is not readily apparent. For example,while apigenin is known to be soluble in basic aqueous solutions,apigenin precipitates from solution upon adjusting the pH with acid. Assuch, another additional consideration is the ability of thesolubilizing agent to assist with maintaining a stable hair carecomposition within the desired pH range. Thus, in another aspect of thepresent invention, a method is provided for selecting ideal solubilizingagents for solubilizing apigenin to facilitate its incorporation intomany different products particularly those in fluid form such as aliquid, a paste, a gel or a cream. Of course, the methods describedherein would also be applicable to other practically insolubleflavonoids (e.g., luteolin) and other practically insoluble hair growthstimulating agents.

The solvents selected for the solubilization method of this embodimentare based upon solubility parameters and cohesion properties explainedby Charles Hansen in “Hansen Solubility Parameters: A User's Handbook”by Charles M. Hansen, CRC Press (2007) and in “The CRC Handbook andSolubility Parameters and Cohesion Parameters,” edited by Allan F. M.Barton (1999). Each material is defined by three points in 3D space andthese three points are known as the Hansen Solubility Parameters (HSP)which may be defined as follows.

Solubility parameters are theoretically calculated numerical constantswhich are a useful tool in predicting the ability of a solvent materialto dissolve a particular solute. When the solubility parameters of asolvent falls within the solubility parameter range of a solute, i.e.,the material to be dissolved, solubilization of the solute is likely tooccur. There are three Hansen empirically- and theoretically-derivedsolubility parameters, a dispersion-force component (δ_(D)), a polar ordipole interaction component (δ_(P)) and a hydrogen-bonding component(δ_(H)). Each of the three parameters (i.e., dispersion, polar andhydrogen bonding) represents a different characteristic of solvency, orsolvent capability. In combination, the three parameters are a measureof the overall strength and selectivity of a solvent. The Total Hansensolubility parameter, which is the square root of the sum of the squaresof the three parameters mentioned previously, provides a more generaldescription of the solvency of the solvents. Individual and totalSolubility Parameter units are given in MPa^(0.5).

Solubility parameters for a material may then be plotted in a normalthree-dimensional graph. From the location (δ_(D), γ_(P), δ_(H)), aradius is projected to form a sphere which encompasses a region ofsolubility such that any solvent whose parameters reside within thisspace should dissolve the solute in question. The distance between theHSP coordinate of material 1 (i.e., the solute) to the HSP coordinatesof material 2 (solvent) is designated herein as Ra. The 3D distance, Ra,is defined by the equation:

Ra ²=4(δ_(D1)−δ_(D2))²+(δ_(P1)−δ_(P2))²+(δ_(H1)−δ_(H2))²

HSPs and the solubility sphere for apigenin are optimized using thefitting method in the software HSPIP version 3.1.06 from Charles M.Hansen Consulting, Horsholm, Denmark, hansen-solubility.com. Qualitativeexperimental solubilities for apigenin in 32 diverse potential solventsare determined using the scoring system at the bottom of Table 1. In thefitting function within HSPiP, solvents with scores of 1 and those withscores of 2-5 are categorized as “good” and “bad” solvents,respectively. Because the fitting procedure in HSPiP does not yield aunique value for HSPiP, the default fitting algorithm is run 50 timesand the following procedure is used to identify the best HSP values fromthis set:

-   -   1. Because the radius can be unbounded, fits with radii larger        than 95% of the radius distribution are removed from these 50        trials (≦8.5 MPa^(0.5)).    -   2. Determine the ranges for δ_(D), δ_(P), δ_(H) for the        remaining fits.    -   3. Locate the fit closest to this point using the Ra equation        above.    -   4. Chose the values for δ_(D), δ_(P), δ_(H) from Step 2 for the        HSP's and the value of Ra from Step 3 for the radius.

Using this protocol, apigenin HSP values and solvent radius aredetermined to be δ_(D)=18.7, δ_(P)=13.5, δ_(H)=13.9 and Ra=6.8 (all inMPa^(0.5)). This sphere defines the initial region encompassing solventsinto which apigenin will be soluble. (Note HSPiP v.3.1.06 is used hereinto determine all HSPs by 1) lookup if available within the program'sinternal database; 2) estimation if not in the database using the Y-MBmethod; or 3) via the procedure described above (apigenin only).)

TABLE 1 Solvents Used to Determine HSP Values for Apigenin With TheirSolubility Scores and HSPs Solvent CAS # δD δP δH Score^(a) Acetone67-64-1 15.5 10.4 7 5 Acetonitrile 75-05-8 15.3 18 6.1 5 1-Butanol71-36-3 16 5.7 15.8 4 n-Butyl Acetate 123-86-4 15.8 3.7 6.3 5 n-ButylAcrylate 141-32-2 15.6 6.2 4.9 5 gamma-Butyrolactone (GBL) 96-48-0 1816.6 7.4 4 Carbon Tetrachloride 56-23-5 17.8 0 0.6 6 Chloroform 67-66-317.8 3.1 5.7 5 Cyclohexane 110-82-7 16.8 0 0.2 6 Cyclohexanol 108-93-017.4 4.1 13.5 4 Cyclohexanone 108-94-1 17.8 8.4 5.1 4 Diacetone Alcohol123-42-2 15.8 8.2 10.8 4 Diethanolamine 111-42-2 17.2 7 19 — DimethylFormamide (DMF) 68-12-2 17.4 13.7 11.3 1 Dimethyl Sulfoxide (DMSO)67-68-5 18.4 16.4 10.2 1 1,4-Dioxane 123-91-1 17.5 1.8 9 5 Ethyl Acetate141-78-6 15.8 5.3 7.2 5 Hexane 110-54-3 14.9 0 0 6 Methanol 67-56-1 14.712.3 22.3 4 Methyl Ethyl Ketone (MEK) 78-93-3 16 9 5.1 5 N-MethylFormamide 123-39-7 17.4 18.8 15.9 1 Methyl Isobutyl Ketone 108-10-1 15.36.1 4.1 5 (MIBK) N-Methyl-2-Pyrrolidone 872-50-4 18 12.3 7.2 1 (NMP)2-Phenoxy Ethanol 122-99-6 17.8 5.7 14.3 4 2-Propanol 67-63-0 15.8 6.116.4 4 Propylene Carbonate 108-32-7 20 18 4.1 5 Propylene Glycol107-98-2 15.6 6.3 11.6 2 Monomethyl Ether Propylene Glycol 108-65-6 15.65.6 9.8 5 Monomethyl Ether Acetate Tetrahydrofuran (THF) 109-99-9 16.85.7 8 4 Toluene 108-88-3 18 1.4 2 6 p-Xylene 106-42-3 17.8 1 3.1 6Dichloromethane 75-09-2 17 7.3 7.1 5 ^(a)Scoring System 1 = CompletelyDissolved 2 = Very Swollen 3 = Swollen 4 = Slightly Swollen 5 = HardlySwollen 6 = Not touched — = Assignment Unclear

Independent, numerical estimates of apigenin solubility may also becomputed using COSMOtherm software, version C21_(—)0111_a (COSMOlogicGmbH & Co. KG, Leverkusen, Germany, www.cosmologic.de.) These estimatesare used to ascertain whether the approximation that a spherical regionin HSP space divides the space into “good” solvents (inside the sphere)and “bad” solvents (outside the sphere). Log 10(X_(sol)) may be computedfor the same 32 solvents used in the experimental solubilitydetermination described above where X_(sol) is the mole fractionsolubility (moles of solute/total moles). The following procedure isused to include apigenin and these solvents in COSMOtherm calculations:

-   -   1. 3D conformers for each compound are generated using the        program Concord (R. S. Pearlman, “Concord,” distributed by        Tripos International, St. Louis, Mo., 63144, USA, tripos.com).    -   2. These conformers are PM3 minimized and each followed by both        gas-phase and infinite dielectric COSMO BP86-TZVP minimizations.    -   3. The BP86-TZVP energies and COSMO charge densities are used as        input to the COSMOtherm solubility module.

Log 10(X_(sol)) is regressed against the 3 sets of HSP values δ_(D),δ_(P), δ_(H) and their cross products. Only δ_(P), δ_(H) and δ_(P)×δ_(H)are significant, which implies that dispersion is not a very importantsolubility parameter for apigenin. As a consequence, the sphericalregion is actually more similar to a cylindrical region. Forsolubility >5% in the selected solvents, the range of δ_(D)(dispersibility) is about 12-22 (MPa)^(0.5) with the polar and hydrogenbonding components (δ_(P) and δ_(H)) falling approximately within a 6.8(MPa)^(0.5) radius around, δ_(P)=13.5 (MPa)^(0.5), δ_(H)=13.9(MPa)*^(0.5).

Non-limiting examples of solubilizing agents, which have suitable HansenSolubility Parameters and may be used to solubilize apigenin includetriethanolamine (CAS No. 102-71-6); diethanolamine (CAS No. 203-868-0);ethanolamine (CAS No. 141-43-5); N-methylformamide (CAS No. 123-39-7);2-dimethylaminoethanol (CAS No. 203-542-8); 2-dimethylamino-2-propanol(108-16-7); ethylenediamine (CAS No. 107-15-3);2-amino-2-methyl-1-propanol (CAS No. 124-68-5); laurocapram (CAS No.59227-89-3); and dimethyl capramide (Spectrasolv, CAS No. 14433-76-2).Non-limiting examples of solvents, which have suitable Hansen SolubilityParameters and may be used in combination with one or more solubilizingagents include dipropyleneglycol (CAS No. 110-98-5); propylene glycol(Hydrolite™ 5, CAS No. 5343-92-0); butylene glycol (CAS No. 107-88-0);1,4-butanediol (CAS No. 110-63-4); 3-allyloxy-1,2-propanediol (CAS No.123-34-2); dipropylene glycol n-butyl ether (CAS No. 29911-28-2);1,2-hexanediol (CAS No. 6920-22-5); dimethyl isosorbide (Arlasolve™ CASNo. 5306-85-4); ethanol (CAS No. 64-17-5); 1,3-butanediol (CAS No.107-88-0); 1,3-propanediol (CAS No. 504-63-2); 2,2′-thiodiethanol (CASNo. 111-48-8); and 1,6-hexanediol (CAS No. 629-11-8). Table 2 provides asummary of various solubilizing agents and solvents and their respectiveHSP values, along with experimentally observed apigenin solubility.

TABLE 2 Exemplary solubilizing agents and solvents, and their respectiveHansen Solubility Parameter (HPS) values. Total ExperimentalSolubilizing Agent CAS δ_(D) δ_(P) δ_(H) HSP Ra solubilitydipropyleneglycol 110-98-5 16 8.7 21.3 28.0 1.5 2.19% at 115 C.propylene glycol 5343-92-0 16.1 8.0 16.9 24.7 1.2 0.62% at 100 C.butylene glycol 107-88-0 16.5 8.1 20.9 27.8 1.5 1.52% at 98 C.1,4-butanediol 110-63-4 16.6 11.0 20.9 28.9 1.3 1.0% at 110 C.3-allyloxy-1,2- 123-34-2 16.2 8.5 16.2 24.4 1.1 1.0% at 120 C.propanediol dipropylene glycol n- 29911-28-2 15.7 6.5 10.0 19.7 1.5 0.6%at 90 C. butyl ether 1,2-hexanediol 6920-22-5 16.0 7.4 16.7 24.3 1.30.4% at 90 C. dimethyl isosorbide 5306-85-4 17.6 7.1 7.5 20.4 1.4 1.54%at 100 C. Ethanol 64-17-5 15.8 8.8 19.4 26.5 1.4 0.32% at 21 C. and 50C. triethanolamine 102-71-6 17.3 7.6 21.0 28.2 1.4 12.7% at 165 C.diethanolamine 108-01-0 16.1 9.2 14.0 23.2 1.0 20.25% at 128 C.ethanolamine 141-43-5 17.0 15.5 21.0 31.1 1.2 20.31% at 76 C.1,3-butanediol 107-88-0 16.5 8.1 20.5 27.5 1.4 1.52% at 98 C.N-methylformamide 123-39-7 17.4 8.8 15.9 25.2 0.8 Ppt upon cooling2,2′-thiodiethanol 111-48-8 17.3 8.8 19.8 27.7 1.2 0.47% at 103 C. 2-108-01-0 16.1 9.2 14.0 23.2 1.0 19.95% at dimethylaminoethanol 29 C.2-dimethylamino-2- 108-16-7 16.6 19.4 18.0 31.2 1.2 20.18% at propanol21 C. ethylenediamine 107-15-3 16.6 8.8 17.0 25.3 1.0 20.03% at 28 C.2-amino-2-methyl-1- 124-68-5 15.7 8.0 15.5 23.5 1.2 20.03% at propanol71 C. 1,6-Hexanediol 629-11-8 15.7 8.4 17.8 25.2 1.3 4.12% at 137 C.1,3-propanediol 504-63-2 16.8 13.5 23.2 31.7 1.5 0.73% at 100 C.Laurocapram^(a) 59227-89-3 17.0 4.4 3.0 17.8 2.1 13.0% at 21 C. Dimethylcapramide^(a) 14433-76-2 16.6 6.7 5.7 18.8 1.7 16.0% at RT ^(a)Not indatabase - estimated using Y-MB method

According to one aspect of the solubilizing agent, the solubilizingagent includes at least one amine functional group therein. Accordingly,the amine functional group can be selected from a primary amine, asecondary amine, a tertiary amine, or an amide. According to oneexample, the solubilizing agent includes a plurality of amine functionalgroups. According to another example, the solubilizing agent includes ahydroxyl functional group. According to another example, thesolubilizing agent includes a plurality of hydroxyl functional groups.According to another example, the solubilizing agent includes at leastone amine functional group and at least one hydroxyl functional group.For example, the solubilizing agent can include an amine functionalgroup and 2 or 3 hydroxyl functional groups. In one example, thesolubilizing agent is triethanolamine. In another example, thesolubilizing agent is dimethylcapramide.

According to another embodiment, the hair care composition may include aplurality of solubilizing agents. For example, it is envisioned thatsynergistic combinations of solubilizing agents may be utilized toachieve enhance solubility characteristics and thereby enable increasedconcentration levels of apigenin and other additional hair growthstimulating agents.

According to another embodiment, the solubilizing agent itself ispresent in an amount of at least 0.15% based on the total composition.The solubilizing agent may be present in amount of greater than about0.2%, 0.5%, 1%, 1.5%, 2%, 3%, 4%, 5%, 6%, 8%, 10%, or 12%. Thesolubilizing agent is typically present in an amount equal to or lessthan about 12%, 10%, 8%, 6%, 5%, 4%, 3%, 2%, 1.5%, 1%, 0.5%, 0.2%, or0.15%.

According to yet another embodiment, the hair care composition mayfurther include one or more solvents, such as dipropyleneglycol,propylene glycol, butylene glycol, 1,4-butanediol,3-allyloxy-1,2-propanediol, dipropylene glycol n-butyl ether,1,2-hexanediol, dimethyl isosorbide, ethanol, 1,3-butanediol,1,3-propanediol, 2,2′-thiodiethanol, and 1,6-hexanediol, or combinationsthereof.

According to yet another embodiment, the hair care composition mayfurther include one or more additional hair growth stimulating agents,such as those disclosed in U.S. Patent Application Publication No.2010/0120871. Accordingly, non-limiting examples of additional hairgrowth stimulating agents include indole compounds, xanthine compounds,vitamin B₃ compounds, panthenol compounds, and derivatives thereof.

A. Indole Compounds

The hair care compositions can further include an indole compound. Asused herein, “indole compound” means one or more indoles, derivativesthereof, mixtures thereof, or salts thereof. Accordingly, thecomposition may include from about 0.1% to about 10% of the indolecompound, from about 0.5% to about 5% of the indole compound, or fromabout 1% to about 2% of the indole compound, for example, wherein thepercentage is a weight percentage based on the total weight of the finalhair care composition.

B. Xanthine Compounds

The hair care compositions can further include a xanthine compound. Asused herein, “xanthine compound” means one or more xanthines,derivatives thereof, and mixtures thereof. Xanthine compounds that canbe useful herein include, but are not limited to, caffeine, xanthine,1-methylxanthine, theophylline, theobromine, derivatives thereof, andmixtures thereof. Accordingly, the composition may include from about0.1% to about 10% of the xanthine compound, from about 0.5% to about 5%of the xanthine compound, or from about 1% to about 2% of the xanthinecompound, for example, wherein the percentage is a weight percentagebased on the total weight of the final hair care composition. Forexample, the hair care composition may further include about 0.75% ofcaffeine.

C. Vitamin B₃ Compounds

The hair care compositions can further include a vitamin B3 compound. Asused herein, “vitamin B₃ compound” means nicotinic acid, niacinamide,nicotinyl alcohol, derivatives thereof, and mixtures thereof. Thevitamin B₃ compound may be included as the substantially pure material,or as an extract obtained by suitable physical and/or chemical isolationfrom natural (e.g., plant) sources. Accordingly, the composition mayinclude from about 0.1% to about 25% of the vitamin B₃ compound; fromabout 0.5% to about 15% of the vitamin B₃ compound; or from about 3.5%to about 7.5% of the vitamin B₃ compound, for example, wherein thepercentage is a weight percentage based on the total weight of the finalhair care composition. For example, the hair care composition mayfurther include about 2.5% of vitamin B₃.

D. Panthenol Compounds

The hair care compositions can further comprise a panthenol compound. Asused herein, the term “panthenol compound” includes panthenol, one ormore pantothenic acid derivatives, and mixtures thereof. Non-limitingexamples of panthenol compounds include D-panthenol([R]-2,4-dihydroxy-N-[3-hydroxypropyl)]-3,3-dimethylbutamide),D,L-panthenol, pantothenic acids and their salts (e.g., the calciumsalt), panthenyl triacetate, royal jelly, panthetine, pantotheine,panthenyl ethyl ether, pangamic acid, pantoyl lactose, Vitamin Bcomplex, or mixtures thereof. Accordingly, the composition may includefrom about 0.01% to about 5% of the panthenol compound; from about 0.03%to about 3% of the panthenol compound; from about 0.05% to about 2% ofthe panthenol compound; or from about 0.1% to about 1% of the panthenolcompound, for example, wherein the percentage is a weight percentagebased on the total weight of the final hair care composition. Forexample, the hair care composition may further include about 0.15% ofpanthenol.

According to another aspect of the present invention, the hair carecompositions may be free of oleanolic acid and/or biotinyl-GHK, which iscontrary to that described in U.S. Patent Application No. 20060067905.

3. Carrier

According to another aspect of the present invention, the hair carecompositions further include at least about 20 weight percent of anaqueous carrier. According to one embodiment, the aqueous carrier may beprepared from demineralized or distilled water, for example. Otheracceptable carriers that may be used in the aqueous carrier include, butare not limited to alcohol compounds, such as ethanol. According to oneembodiment, the composition comprises alcohol, dipropylene glycol,and/or water.

The hair care compositions have a pH ranging from about 3.0 to about 10,which may be measured by taking a direct pH measurement using a standardhydrogen electrode of the composition at 25° C. Accordingly, the pH ofthe hair care composition may be within the range from about 6 to about9, for example.

4. Optional Ingredients

The compositions of the present invention can also additionally compriseany suitable optional ingredients as desired. For example, thecomposition can optionally include other active or inactive ingredients.

The compositions may include other common hair ingredients such aspyrithione zinc, minoxidil, silicones, conditioning agents, and othersuitable materials. The CTFA Cosmetic Ingredient Handbook, Tenth Edition(published by the Cosmetic, Toiletry, and Fragrance Association, Inc.,Washington, D.C.) (2004) (hereinafter “CTFA”), describes a wide varietyof nonlimiting materials that can be added to the composition herein.Examples of these ingredient classes include, but are not limited to:abrasives, absorbents, aesthetic components such as fragrances,pigments, colorings/colorants, essential oils, skin sensates,astringents, etc. (e.g., clove oil, menthol, camphor, eucalyptus oil,eugenol, menthyl lactate, witch hazel distillate), anti-acne agents,anti-caking agents, antifoaming agents, antimicrobial agents (e.g.,iodopropyl butylcarbamate), antioxidants, binders, biological additives,buffering agents, bulking agents, chelating agents, chemical additives,colorants, cosmetic astringents, cosmetic biocides, denaturants, drugastringents, external analgesics, film formers or materials, e.g.,polymers, for aiding the film-forming properties and substantivity ofthe composition (e.g., copolymer of eicosene and vinyl pyrrolidone),opacifying agents, pH adjusters, propellants, reducing agents,sequestrants, rheology modifiers, hair conditioning agents, andsurfactants.

In one embodiment, the composition comprises a rheology modifier toincrease the substantivity of the composition, such that it does notdrip undesirably onto other areas of the body, onto clothing, or ontohome furnishings and may also perform as a film former, therebyincreasing the delivery of apigenin to the hair follicle and surroundingtissue. Any suitable rheology modifier can be used, for example, acellulose-based rheology modifier, such as hydroxypropylmethylcellulose.Other non-limiting examples of rheology modifiers includeacrylamide/ammonium acrylate copolymer (and) polyisobutene (and)polysorbate 20; acrylamide/sodium acryloyldimethyl tauratecopolymer/isohexadecane/polysorbate 80; acrylates copolymer;acrylates/beheneth-25 methacrylate copolymer; acrylates/C10-C30 alkylacrylate crosspolymer; acrylates/steareth-20 itaconate copolymer;ammonium polyacrylate/Isohexadecane/PEG-40 castor oil; C12-16 alkylPEG-2 hydroxypropylhydroxyethyl ethylcellulose (HM-EHEC); carbomer;crosslinked polyvinylpyrrolidone (PVP); dibenzylidene sorbitol;hydroxyethyl ethylcellulose (EHEC); hydroxypropyl methylcellulose(HPMC); hydroxypropyl methylcellulose (HPMC); hydroxypropylcellulose(HPC); methylcellulose (MC); methylhydroxyethyl cellulose (MEHEC);PEG-150/decyl alcohol/SMDI copolymer; PEG-150/stearyl alcohol/SMDIcopolymer; polyacrylamide/C13-14 isoparaffin/laureth-7; polyacrylate13/polyisobutene/polysorbate 20; polyacrylate crosspolymer-6;polyamide-3; polyquaternium-37 (and) hydrogenated polydecene (and)trideceth-6; polyurethane-39; sodiumacrylate/acryloyldimethyltaurate/dimethylacrylamide; crosspolymer (and)isohexadecane (and) polysorbate 60; sodium polyacrylate. Exemplarycommercially-available rheology modifiers include ACULYN™ 28, Klucel MCS, Klucel H CS, Klucel G CS, SYLVACLEAR AF1900V, SYLVACLEAR PA1200V,Benecel E10M, Benecel K35M, Optasense RMC70, ACULYN™33, ACULYN™46,ACULYN™22, ACULYN™44, Carbopol Ultrez 20, Carbopol Ultrez 21, CarbopolUltrez 10, Carbopol 1342, Sepigel™ 305, Simulgel™600, Sepimax Zen, andcombinations thereof.

The formulations of the present invention may be present in typical haircare compositions. They may be in the form of solutions, dispersion,emulsions, powders, talcs, encapsulated, spheres, spongers, solid dosageforms, foams, and other delivery mechanisms. The composition of thepresent invention may be hair tonics, leave-on hair products such asconditioners, treatment, and styling products, rinse-off hair productssuch as conditioners, shampoos, and treatment products; and any otherform that may be applied to the hair and preferably applied to thescalp.

As disclosed herein, the hair care composition contains apigenin. Inembodiments where one or more indole compounds, one or more xanthinecompounds, one or more vitamin B₃ compounds, and/or one or morepanthenol compounds are present, the apigenin may be in the a singlephase or a single product, or the apigenin may be in a separate phase orseparate product. If two products are used, the products may be usedtogether, at the same time or sequentially. Sequential use may occur ina short period of time, such as immediately after the use of oneproduct, or it may occur over a period of hours or days.

According to one embodiment, the hair care composition includes greaterthan 0.005% to about 5% apigenin; from about 0.15% to about 12% of thesolubilizing agent; at least about 20% of the aqueous carrier; andfurther includes from about 0% to about 5% of the conditioning agent;from about 0% to about 5% of the moisturizing agent; from about 0% toabout 10% of the penentrant agent; from about 0% to about 50% of theorganic solvent; from about 0% to about 10% of the neutralizing agent;from about 0% to about 20% of the rheology modifier; from about 0% toabout 20% of the surfactant; from about 0% to about 3% of the fragranceagent; from about 0 wt % to about 3 wt % of the aesthetics enhancer, orfrom about 0 wt % to about 10 wt % of the partitioning agent. Accordingto another embodiment, the hair care composition further includesfurther includes from about 0.1% to about 5% of the conditioning agent;from about 0.5% to about 5% of the moisturizing agent; from about 0.05%to about 10% of the penentrant agent; from about 0.5% to about 50% ofthe organic solvent; from about 0.1% to about 10% of the neutralizingagent; from about 0.5% to about 20% of the rheology modifier; from about0.1% to about 20% of the surfactant; from about 0.1% to about 3% of thefragrance agent; from about 0.1% to about 3% of the aesthetics enhancer,or from about 0.1% to about 10% of the partitioning agent.

B. Method of Making the Hair Care Compositions

According to another embodiment of the invention, a process forpreparing a hair care composition includes mixing apigenin and asolubilizing agent at a temperature sufficient to allow dissolution ofthe apigenin in the solubilizing agent to form a premixture; combiningthe premixture with an aqueous carrier to form the hair carecomposition; and optionally, adjusting the pH of the hair carecomposition with acid to within a range from about 3 to about 10. Thepremixture is prepared by combining apigenin and one or moresolubilizing agents. Solubilization energy (e.g., stirring, sonication,milling, heat, etc.) may be applied to accelerate the dissolutionprocess. For example, a premixture of apigenin in triethanolamine may beprepared by combining apigenin and triethanolamine in a single vesseland heating the mixture to 70° C. while stirring until a clear solutionresults. According to one aspect of the exemplary method of making thepremixture, the combined apigenin and triethanolamine are mixed at50-100 rpm using a IKA RET CV-S1 mixer. According to another aspect, thecombination is mixed at 300-500 rpm using a IKA Eurostar PWR CV-S1mixer.

According to one aspect of the method, the weight ratio of apigenin tosolubilizing agent ranges from about 1:50 to about 1:4. For example, theweight ratio may be about 1:45, about 1:40, about 1:35, about 1:30,about 1:25, about 1:20, about 1:15, about 1:10, about 1:8, about 1:5, orwithin a range between the recited values. The weight of thesolubilizing agent includes the weight of all the solubilizing agentsused in making the premixture.

According to another aspect, the pH is adjusted to the desired valuewithin the range from about 3 to about 10 using an acid. For example,the pH may be about 4, about 5, about 6, about 7, about 8, about 9, orwithin a range between the recited values. According to one embodiment,the pH is adjusted with an acid to within a range from about 6.5 toabout 9. Exemplary acids include carboxylic acids, such as citric acid,and mineral acids, such as hydrochloric acid.

According to another aspect, the method further includes adding arheology modifier to the hair care composition to obtain a rheologyvalue in the range from about 30 cPs to about 50,000 cPs. For example,the rheology value may be about 50 cPS, about 100 cPs, about 300 cPs,about 500 cPs, about 1,000 cPs, about 10,000 cPs, about 25,000 cPs, orwithin a range between the recited values. Exemplary rheology modifiersinclude those available under the tradenames ACULYN™ 28, Klucel M CS,Klucel H CS, Klucel G CS, SYLVACLEAR AF1900V, SYLVACLEAR PAl200V,Benecel E10M, Benecel K35M, Optasense RMC70, ACULYN™33, ACULYN™46,ACULYN™22, ACULYN™44, Carbopol Ultrez 20, Carbopol Ultrez 21, CarbopolUltrez 10, Sepigel™ 305, Simulgel™600, Sepimax Zen, Carbopol 1342, andcombinations thereof.

C. Method for Increasing the Appearance of Thicker and Fuller Hairand/or Delaying the Appearance of Gray Hair

According to yet another embodiment of the present invention, a methodis provided for increasing the diameter of the hair shaft and follicle;increasing the density of hair follicles; and/or delaying the appearanceof gray hair. This may lead to an appearance of thicker and/or fullerhair and may lead to the appearance of delayed onset of gray hair. Inone aspect, the method comprises applying the hair care composition to askin surface from which a region of hair grows. For instance, the haircare composition can be applied to the scalp. In another embodiment, themethod comprises topically applying a hair care composition comprisingan effective amount of apigenin to a region of skin of a mammal seekingto increase the appearance of thicker and/or fuller hair or delaying theappearance of gray hair.

In still another embodiment, the method comprises applying thecomposition according to a regimen, wherein said regimen comprises:

(a) cleansing the scalp to form a cleansed scalp;

(b) topically applying the composition to said cleansed scalp.

The hair care composition may be used daily, weekly, or in a variety ofregimens. The hair care composition may be used more than once a day,such as at night and in the morning. The product may be used afterwashing the hair (also on wet or dry hair), which may mean using thecomposition more than once per day on certain days or use only a fewtimes per week. The hair care composition may be used three times perday, twice per day, once per day, six times per week, five times perweek, four times per week, three times per week, two times per week, orone time per week. In some embodiments, the hair care composition isused four, five, six or seven times per week.

The hair care composition may be used by males and females. The haircare composition may be desired to be used by individuals who desire topromote hair growth or have healthier or younger looking hair. Forexample, the hair care composition may be used on subjects who have nodiagnosed hair loss. The hair care composition may be used on subjectshaving an age of greater than about 20, 25, 30, 35, 40, 45, or 50. Thehair care composition may be used on subjects having an age of less thanabout 70, 65, 60, 55, or 50. Accordingly, the hair care composition maybe used on subjects between the ages of about 20-70, from about 30-60,and from about 35-55. Hair diameter may start to decrease after age 20so healthier hair and increased appearance of fuller and thicker hairmay be desired after these ages. Hair diameter continues to decrease andin some subject to a greater extent after age 30 or 40. Additionally,gray hair begins to emerge as early as age 20 but more commonly afterage 30 or 40 depending upon genetics.

Formulations and Examples

The following are non-limiting examples of the present invention. Theexamples are given solely for the purpose of illustration and are not tobe construed as limitations of the present invention, as many variationsthereof are possible without departing from the spirit and scope of theinvention, which would be recognized by one of ordinary skill in theart.

In the examples, all concentrations are listed as weight percent, unlessotherwise specified and may exclude minor materials such as diluents,filler, and so forth. The listed formulations, therefore, comprise thelisted components and any minor materials associated with suchcomponents. As is apparent to one of ordinary skill in the art, theselection of these minors will vary depending on the physical andchemical characteristics of the particular ingredients selected to makethe present invention as described herein. Triethanolamine isabbreviated TEA.

TABLE 3 Exemplary results of preparing apigenin premixtures with varioussolubilizing agents. Temperature Mixing Speed Solubility SolubilizingAgent (° C.) (rpm) (mg/ml) 1-Dimethylamino-2-propanol room temp 300 9.501-Dimethylamino-2-propanol room temp 300 20.181-Dimethylamino-2-propanol solution room temp 300 20.201-Dimethylamino-2-propanol solution room temp 1500 sm 20.001-Dimethylamino-2-propanol/Ethanolamine room temp 300 16.561-Dimethylamino-2-propanol/Ethanolamine/TEA room temp 300-500 16.481-Dimethylamino-2-propanol/Ethylenediamine room temp 400-600 20.061-Dimethylamino-2-propanol/TEA room temp 300-810 17.28 1-Methylimidazole82 100 20.45 2-Dimethylaminoethanol 29 300 19.95 2-Dimethylaminoethanolroom temp 300 20.15 2-amino-2-methyl-1-propanol 71 450 14.832-amino-2-methyl-1-propanol 71 400 20.03 Diethanolamine 128  550 20.25Ethanolamine 76 300 20.31 Ethanolamine room temp 350-740 20.20Ethanolamine 29 350-500 20.13 Ethanolamine/TEA 29 300-600 18.01Ethanolamine/TEA room temp 350-500 15.95 Ethylenediamine 28 320 20.03Ethylenediamine room temp 320 20.15 Laurocapram, 98% 140  500-600 14.03Laurocapram, 98% room temp 500-600 13.90 N-Methylformamide 101  40013.65 Pyridine room temp 300 15.75 Synthetic Apigenin in Ethanolamine 76400 20.17 Synthetic Apigenin in TEA 169  450 14.72 TEA room temp 450-59020.04 TEA/1-Dimethylamino-2-propanol room temp 350-450 17.01TEA/1-Dimethylamino-2-propanol/Ethylenediamine room temp 330-600 20.59TEA/2-Dimethylaminoethanol/1-Dimethylamino-2- room temp 330-400; 150015.00 propanol sm TEA/2-Dimethylaminoethanol/1-Dimethylamino-2- roomtemp 1500 sm 15.00 propanolTEA/2-Dimethylaminoethanol/1-Dimethylamino-2- room temp 1500 sm 15.00propanol Triethylene glycol 156  300 6.11 Dimethyl capramide Room temp400 16.00 Triethylenamine TEA/Dimethyl capramide TEA/Triethylenamine

Exemplary additives, which are used in preparing exemplary formulationsof the hair care compositions in accordance with embodiments of thepresent invention, are provided in Table 4.

TABLE 4 Exemplary components for the hair care compositions. EntryIngredients Role Concentrations Range 1 Ethanol alcohol/solvent 20%,21%, 50%, 57%, 70% 20-80% 2 Water carrier QS QS 3 Tween 80 nonionicsurfactant 0%, 2.5%, 5%, 10%  0-10% 4 Hydrolite-5 alcohol/solvent 0%,2.5%, 5%, 10%  0-10% 5 Dipropylene Glycol alcohol/solvent 0%, 5%, 50% 0-50% (DPG) 6 Arlasolve DMI high purity solvent 0%, 8% 0-8% (dimethylisosorbide) 7 Apigenin anti-inflammatory 0.32%, 0.50%, 1% <1-1%  8Triethanolamine solvent/neutralizer 0%, 1.30%, 1.89%, 2.44%, 2.46%,<4.00% 3.99%, 19%, 9.50%, 11.50%, 12.26% 9 Citric Acid Neutralizer 0-3%  <3% 10 Eastman DE Solvent solvent   10%  0-30% (Transcutol -Diethylene glycol monoethyl ether) 11 Eldew SL-205 solvent   50%  0-60%12 SF 1202 Silicone fluid moisturizer   19%  0-50% 13 PEG 10 Dimethiconemoisturizer   1% 0-3% 14 Vitamin E Acetate skin penetration 0.50% 0-3%enhancement, moisturizer 15 Hexylene Glycol skin penetration   5%  0-10%enhancement 16 Oleic Acid skin penetration   1% 0-5% enhancement 17Panthenol conditioning agent 0.15% 0-5% 18 Niacinamide conditioningagent 2.50%  0-25% 19 Caffeine conditioning agent 0.75%  0-10% 20 WakanaHE Fragrance   1% 0-5% 21 ACULYN ™28 rheology modifier 1.25%, 2.5%,3.75%, 5%, 7.5%, 0.10-17.5% 10%, 12.5%, 17.5%Other exemplary partitioning agents, such as triethylene glycol (0-10%),propylene carbonate (0-10%), or hexylene glycol (0-10%); and otherpenetration enhancers, such as oleic Acid (0-5%) or vitamin E Acetate(0-1%).

To prepare the hair care compositions using the premixture of apigeninand the solubilizing agent, exemplary order of mixing of the ingredientsand the premixture are provide in Table 5, wherein reference to theingredients in the Order of Addition is with respect to the entrynumbers of Table 4.

TABLE 5 Exemplary mixing methods for preparing the hair carecompositions. Entry Order of Addition Mixing Steps A 2, 21, 1, 8 + 7,20, 9, 2 IKA Overhead mixer and/or High speed mixer B 2, 21, 1, 8 + 7,20, 17, 18, 19, 9, 2 IKA Overhead mixer and/or High speed mixer C 2, 21,1, 8 + 7, 15, 14, 16, 20, 9, 2 IKA Overhead mixer and/or High speedmixer D 2, 21, 1, 8 + 7, 13, 20, 9, 2 IKA Overhead mixer and/or Highspeed mixer E 2, 21, 5, 6, 4, 3, 8 + 7 IKA Overhead mixer and/or Highspeed mixer F 2, 1, 21, 8 + 7, 3, 9, 2 IKA Overhead mixer and/or Highspeed mixer G 4, 2, 3, 6, 7, 1, 21 IKA Overhead mixer H 2, 3, 21, 8 + 7,1, 9, 2 IKA Overhead mixer and/or High speed mixer I 2, 1, 8 + 7, 9, 2IKA Overhead mixer and/or High speed mixer J 2, 1, 3, 8 + 7, 9, 2 IKAOverhead mixer and/or High speed mixer K 2, 21, 1, 8 + 7, 9, 2 IKAOverhead mixer and/or High speed mixer L 2, 21, 8 + 7, 1, 3, 9, 2 IKAOverhead mixer and/or High speed mixer M 8 + 7, 2, 1, 5, 6, 4, 3 IKAOverhead mixer N 1, 7, 10, 11, 12 IKA Overhead mixer

In Vitro Skin Penetration General Protocol

In vitro skin penetration of actives, such as apigenin, from topicallyapplied formulations is determined using the Franz diffusion cell assay.The method is widely used in the skin care industry for assessment ofskin penetration and for the dermal absorption safety assessments. SeeFranz, T. J. Percutaneous absorption. On the relevance of in vitro data.J. Invest. Dermatol. 64: 190-195, 1975; Franz, et al. The use of excisedhuman skin to assess the bioequivalence of topical products. SkinPharmacol. Physiol. 22: 276-286, 2009; and OECD Guideline (#428) for theTesting of Chemicals, Adopted 13 Apr. 2004. A diffusion assay method isdescribed in general below:

Split-thickness human cadaver skin (Allosource, Englewood, Colo.) ordermatomed pig skin is thawed at ambient conditions, cut intoappropriately sized sections, and then mounted in standard Franz-typediffusion cells (0.79 cm² surface area) maintained at about 37° C. Thereceptor compartments [˜5 mL] are filled with phosphate buffered saline(PBS—pH 7.4) that included 1% polysorbate-20 and 0.02% sodium azide, andthe skin is allowed to equilibrate for two hours. The cells arerandomized to treatment based upon ³H₂O flux through the mounted skin(150 μL of ³H20 applied for five minutes and removed). Diffusion cellsare randomized by ranking each cell according to water flux anddistributing cells across treatment legs such that each group includescells across the range of observed water flux. Each treatment grouptypically has 6 replicates.

Aliquots of the test products/formulations are spiked with theappropriate radioactive material (i.e. ¹⁴C-niacinamide) withapproximately 3 μCi per 300 mg product aliquot, mixed and as-sayed fortotal radioactivity in triplicate using Ultima Gold [Perkin-Elmer]liquid scintillation cocktail (LSC) and liquid scintillation counting(Tri-Carb 2500 TR Liquid Scintillation Analyzer, PerkinElmer, Boston,Mass.).

Skin is topically dosed with 5 μL of product using a positivedisplacement pipette. The product is gently spread over the surface ofthe skin (0.79 cm²) using the pipet tip. The receptor solution iscollected and replaced at various time points following application(i.e. 2, 4 and 6 hrs) with a final collection at 24 hrs. Skin is alsocollected at (6 hours if specified) and 24 hours post-application. Afterthe final receptor collection for each study leg, each skin sample iswiped two times with Whatman filter paper soaked with PBS/Tween 20 andonce with 70%/30% ethanol/water to remove unabsorbed (residual) product.The epidermis is separated from the residual dermis by dissection. Theskin sections are dissolved in 0.50-1.25 mL Soluene-350 (Perkin Elmer,Boston, Mass.) at 50° C. overnight, and all receptor collections, filterpaper wipes, and solubilized tissue sections are counted using liquidscintillation counting as described previously. In experiments whereradioactive tracers are not available, analytical methods, such as LCMS,are developed for the active material of interest.

Disintegrations-per-minute (DPMs) for each compartment of each cell areblank corrected and summed to obtain a total recovered radiolabel valuefor a given cell. The DPMs of each compartment are then normalized tothe total recovered radiolabel value to obtain a “percent recoveredradiolabel” parameter for each compartment (individual receptorcollections, epidermis, dermis, and wipes for mass balance). Cumulativereceptor values to each collection time point are calculated as the sumof the individual collections to that time point, with the totalreceptor value as the sum of all individual collections. The total skinvalue is the sum of the epidermis (including stratum corneum) and dermisvalues, and the total permeated value the sum of total skin andcumulative receptor values. Skin penetration data are typicallyexpressed as % of applied dose, % of recovered dose (normalized for massbalance) and/or ug/cm².

Samples, in accordance with an embodiment of the invention, can beprepared and tested using the in vitro skin penetration protocoldescribed above. Sample A includes 0.32 wt % apigenin, 50 wt % ethanol,7.5 wt % Aculyn™ 28, 38.72 wt % water, 2.46 wt % triethanolamine, 1 wt %Wakana HE, and 0.75 wt % citric acid, and has a pH of 7.0. Sample Bincludes 1 wt % apigenin, 50 wt % ethanol, 7.5 wt % Aculyn™ 28, 32.8 wt% water, 7.7 wt % triethanolamine, 1 wt % Wakana HE, and 2.42 wt %citric acid, and has a pH of 7.2. Comparative Sample includes 1 wt %apigenin, 20 wt % ethanol, 10 wt % Hydrolite®-5, 50 wt %dipropyleneglycol, 10 wt % Tween 80, 8 wt % Arlasolve™ DMI PC, and 1 wt% Klucel, and has a pH of 7.0.

Table 6 demonstrates that apigenin-containing compositions of thepresent invention provide enhanced skin penetration compared with knowncompositions using traditional solubilizing agents.

TABLE 6 Comparative Skin Penetration data of various hair carecompositions. Comparative Sample Sample A Sample B Mean 2.18 4.42 8.30sem 0.32 0.37 0.98

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue.

For example, a dimension disclosed as “40 mm” is intended to mean “about40 mm.”

All documents cited in the Detailed Description of Embodiments of theInvention are, in relevant part, incorporated herein by reference; thecitation of any document is not to be construed as an admission that itis prior art with respect to the present invention. To the extent thatany meaning or definition of a term in this document conflicts with anymeaning or definition of the same term in a document incorporated byreference, the meaning or definition assigned to that term in thisdocument shall govern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

1. A hair care composition comprising: a) from about 0.15 wt % to about5% wt % apigenin; b) from about 1% to about 12% of a solubilizing agent,wherein the solubilizing agent comprises an amine functional group; andc) at least 20 weight percent of an aqueous carrier, and d) from about0.5 wt % to about 20 wt % of a rheology modifier, wherein the rheologymodifier is an acrylate copolymer; wherein the composition has a pHranging from about 3 to about
 10. 2. The hair care composition of claim1, wherein the solubilizing agent has individual Hansen solubilityparameters of a dispersion force component (δ_(D)) ranging from about 12to about 22 (MPa)^(0.5), a polar component (δ_(P)) ranging from about6.7 to about 20.3 (MPa)^(0.5) and a hydrogen bonding component (δ_(H))ranging from about 7.1 to about 20.7 (MPa)^(0.5).
 3. The hair carecomposition of claim 1, wherein the solubilizing agent has individualHansen solubility parameters of a dispersion force component (δ_(D))ranging from about 12 to about 22 (MPa)^(0.5) and polar and hydrogenbonding components (δ_(P) and δ_(H)) falling approximately within a 6.8(MPa)^(0.5) radius around, δ_(P)=13.5 (MPa)^(0.5), δ_(H)=13.9(MPa)^(0.5).
 4. The hair care composition of claim 1, wherein the aminefunctional group of the solubilizing agent is selected from the groupconsisting of a primary amine, a secondary amine, a tertiary amine, andan amide.
 5. The hair care composition of claim 1, wherein the aminefunctional group of the solubilizing agent is a tertiary amine.
 6. Thehair care composition of claim 1, wherein the solubilizing agent furthercomprises a hydroxyl functional group.
 7. The hair care composition ofclaim 1, wherein the solubilizing agent is selected from the groupconsisting of 2-dimethylaminoethanol, 1-dimethylamino-2-propanol,triethanolamine, ethylenediamine, diethanolamine, ethanolamine,2-amino-2-methyl-1-propanol, dimethyl capramide and combinationsthereof.
 8. The hair care composition of claim 1, wherein thesolubilizing agent is triethanolamine.
 9. The hair care composition ofclaim 1, further comprising a plurality of solubilizing agents.
 10. Thehair care composition of any preceding claim further comprising aconditioning agent, a moisturizing agent, a penetrant agent, an organicsolvent, a neutralizing agent, a surfactant, a fragrance agent, anaesthetics enhancer, a partitioning enhancer, or combinations thereof.11. The hair care composition of claim 10, wherein the conditioningagent is present in an amount within the range from about 0.1 wt % toabout 5 wt %; the moisturizing agent is present in an amount within therange from about 0.5 wt % to about 5 wt %; the penetrant agent ispresent in an amount within the range from about 0.05 wt % to about 10wt %; the organic solvent is present is present in an amount within therange from about 0.5 wt % to about 50 wt %; the neutralizing agent ispresent in an amount within the range from about 0.1 wt % to about 10 wtthe surfactant is present in an amount within the range from about 0.1wt % to about 20 wt %; the fragrance agent is present in an amountwithin the range from about 0.1 wt % to about 3 wt %, the aestheticsenhancer is present in an amount ranging from about 0.1 wt % to about 3wt %, or the partitioning agent is present in an amount ranging fromabout 0.1 wt % to about 10 wt %, wherein the wt % is based on the totalweight percent of the hair composition.
 12. The hair care composition ofclaim 1, further comprising a xanthine compound, a vitamin B₃ compound,a panthenol compound, or mixtures thereof.
 13. The hair care compositionof claim 12, wherein the xanthine compound is present in an amountranging from about 0.1 wt % to about 10 wt %; the vitamin B₃ compound ispresent in an amount ranging from about 0.1 wt % to about 25 wt %; orthe panthenol compound is present in an amount ranging from about 0.01wt % to about 3 wt %, wherein weight percent is based on the totalweight of the hair composition.
 14. A process for preparing a hair carecomposition comprising: a) mixing apigenin and a solubilizing agent at atemperature sufficient to allow dissolution of the apigenin in thesolubilizing agent to form a premixture, wherein the weight ratio ofapigenin to the solubilizing agent ranges from about 1:50 to about 1:4;b) combining the premixture with an aqueous carrier to form the haircare composition; and c) optionally, adjusting a pH of the hair carecomposition with an acid to within a range from about 3 to about
 10. 15.The process of claim 13, wherein the weight ratio of apigenin to thesolubilizing agent is within the range from about 1:10 to about 1:4. 16.The process of claim 14, further comprising d) adding a rheologymodifier to the hair care composition to obtain a rheology value in therange from about 30 cPs to about 50,000 cPs.
 17. The process of claim16, wherein the rheology value is in the range from about 300 to about5,000 cPs.
 18. The process of claim 16, wherein the rheology modifier isselected from the group consisting of hydroxypropylmethylcellulose; amixture of acrylamide/ammonium acrylate copolymer, polyisobutene, andpolysorbate 20; acrylamide/sodium acryloyldimethyl tauratecopolymer/isohexadecane/polysorbate 80; acrylates copolymer;acrylates/beheneth-25 methacrylate copolymer; acrylates/C10-C30 alkylacrylate crosspolymer; acrylates/steareth-20 itaconate copolymer;ammonium polyacrylate/Isohexadecane/PEG-40 castor oil; C12-16 alkylPEG-2 hydroxypropylhydroxyethyl ethylcellulose (HM-EHEC); carbomer;crosslinked polyvinylpyrrolidone (PVP); dibenzylidene sorbitol;hydroxyethyl ethylcellulose (EHEC); hydroxypropyl methylcellulose(HPMC); hydroxypropyl methylcellulose (HPMC); hydroxypropylcellulose(HPC); methylcellulose (MC); methylhydroxyethyl cellulose (MEHEC);PEG-150/decyl alcohol/SMDI copolymer; PEG-150/stearyl alcohol/SMDIcopolymer; polyacrylamide/C13-14 isoparaffin/laureth-7; polyacrylate13/polyisobutene/polysorbate 20; polyacrylate crosspolymer-6;polyamide-3; polyquaternium-37 (and) hydrogenated polydecene (and)trideceth-6; polyurethane-39; sodiumacrylate/acryloyldimethyltaurate/dimethylacrylamide; crosspolymer (and)isohexadecane (and) polysorbate 60; sodium polyacrylate and combinationsthereof.
 19. The process of claim 14, wherein the pH of the hair carecomposition is adjusted with an acid to within a range from about 6.5 toabout 9, and optionally wherein the acid is citric acid or hydrochloricacid
 20. A method of affecting a healthier hair appearance comprisingthe steps of: administering an effective amount of the hair carecomposition of any claim 1-12 to at least one first portion of a scalpof said subject, wherein the healthier hair appearance includes treatinghair loss in a subject in need of such treatment, delaying theappearance of gray mammalian hair of a subject, or increasing theappearance of fuller and thicker mammalian hair of a subject.